why doesn't holden throw the snowball?

Holden doesn't throw the snowball because for some reason he just can't let it

"It took him [Ackley] about five hours to get ready. While he was doing it, I went over to my window and opened it and packed a snowball with my bare hands. The snow was very good for packing. I didn’t throw it at anything, though. I started to throw it. At a car that was parked across the street. But I changed my mind. The car looked so nice and white. Then I started to throw it at a hydrant, but that looked too nice and white, too. Finally I didn’t throw it at anything. All I did was close the window and walk around the room with the snowball, packing it harder. A little while later, I still had it with me when I and Brossard and Ackley got on the bus. The bus driver opened the doors and made me throw it out. I wasn’t going to chuck it at anybody, but he wouldn’t believe me. People never believe you."

that should read for some reason he cannot let it go........ sorry!